2013 한국미생물학회연합 국제학술대회, 2013, 02, F052─F052

Characterization of Glycosyl hydrolase Family Proteins Deficient Mutants of Streptococcus pneumoniae

Sungkyoung Lee, Darum Lee, Ji-Hye Kim, Seoung-Han Kim, Misun Park, Songmee Bae

Abstract

In Streptococcus pneumoniae, a transition switch from colonization to systemic disease has been involved with phenotypic phase variation from transparent to opaque. Global gene expression patterns of two phase variants showed the possibility of the correlation between glycosyl hydrolase family-related genes and phase variation. Thus, we constructed five mutants of S. pneumoniae, lack of GH13, GH20, GH32, GH38 and GH125, to elucidate the link of glycosyl hydrolase family-related proteins to pneumococcal pathogenesis. Five knockout mutants exhibited slower growth rate than the parent strain. GH13, GH32, GH38 and GH125 mutants decreased the production of the capsule, a key pneumococcal virulence factor. The GH13 and GH32 mutants resulted in a defect in the ability of adherence to A549 lung epithelial cells. We investigated the changes of trans in GH13 and GH32 mutants to observe the association of virulence by DNA microarray. Various genes related to sugar metabolism, PTS systems and heat-shock proteins were up-regulated in both mutant strains. Phn (phosphate utilization) was down regulated in GH13 mutant and aliA associated capsule biosynthesis were down-regulated in GH32. Along with virulence study using infection models, a role of glycosyl hydrolase family-related proteins can be elucidated in pneumococcal pathogenesis.

• 본 연구는 질병관리본부 연구개발과제(과제번호 2012-N46003-00) 연구비를 지원받아 수행되었습니다.
• This research was supported by a fund(code 2012-N46003-00) by Research of Korea Centers for Disease Control and Prevention.